I use a soft MF with Plexus, and get outstanding results...
Pete
That is what I use (Plexus Plastic Aerosol) and the suede microfiber I have comes from Korea for cleaning plastic, and it is dedicated to cleaning plastic lens ONLY. I also use the Meg Mirror Glaze Plastic Twins (#17 Cleaner and #10 Polish) to polish out scratches, but I do not have a lot of success with them!
Most plastic lens scratches are caused by:
1) Dirt or dust on the lens itself. It is best to clean this first with some type of mild APC and a very soft microfiber (like Meg`s Detailer Line D101 APC diluted 10:1)
2) Using an ammoniated window cleaner (Like Windex or bargain window sprays). Specific plastic cleaners/polishes should ONLY be used.
3) Wiping them off with paper toweling. Use only as soft suede-type microfiber.
I see that
McKee`s 37 has a similar product to Plexus, called Plex-All. One thing about Plexus is that it is very expensive and I have found it over-the-counter (OTC) at boating/sailing supply shops in my area. I also found the Novus line of plastic cleaner/polishes (there are four of them, #1 thru #4) at a local plastic supply company that sells Plexiglass (AKA, polycarbonate clear plastic) to local food and paper processing machine manufacturers for operator guarding and hockey rinks for their end board "glass" to protect fans.
Now that I think of it, there are a number of eye-glass spray cleaners and microfiber clothes (Ziess comes to mind) that may be applicable to the cleaning of plastic instrument panel lens/covers, seeing how most eyeglass lenses are now made of polycarbonate. Humm....!
AND, since we are on the subject of plastics,
Bio-Kleen makes a screen cleaner and microfiber kit for touch screens. This, again, was something I found at the boating/sailing supply shop and was told that sailors liked it for GPS navigation screens and boaters for their fish-locating screen. I know that many vehicles now come standard with some type of touch screen for information/navigation and vehicle controls, and getting the finger prints off can be a real pain without damaging or scratching the screen!